Typically, closures for powdered products consist of a lid having one or more holes, through which the product is dispensed. When not in use, the holes in the lid are protected by a cover. Usually, this cover is attached to the lid via a hinge. In order to dispense the product, the consumer removes the cover to expose the holes and then dispenses the product through the holes. This type of container does not normally provide for an airtight seal, without which the product very often has an adverse reaction with the atmosphere outside of the container.
Other powdered product closures comprise a stationary first lid having one or more holes, and a rotatable second lid having one or more holes. By its operation, the consumer rotates the second lid with respect to the first lid until the holes within each are aligned. When the holes are aligned, the consumer dispenses the product. The problem with this style closure is that it is not self-closing. The consumer often forgets to turn the second lid into the closed position after dispensing, thus leaving the container in the open position and making it easy to spill the contents of the container. Also, when the consumer does turn the second lid into the closed position, the amount of turning used by the consumer is often insufficient to properly close the lid, thereby leaving the contents exposed to the atmosphere outside of the container.
French Patent 2645511 discloses a closure for a powdered product which is self-closing. The closure comprises a first lid having at least one orifice, and a second lid slidably disposed about the first lid, the second lid having at least one orifice. By sliding the second lid, the consumer aligns the holes of the first and second lids such that the product can be dispensed. After the consumer has finished dispensing the desired amount of product, a spring between the first lid and the second lid pushes the second lid into the closed position. It is claimed that this structure gives an airtight closure. This, however, is only possible with precise molding of the first lid and the second lid in the area in which the two meet. As shown in the disclosure, the two opposing surfaces which meet have to be perfectly flat. Without this, an airtight seal cannot be made. Because these two surfaces have varying dimensions due to the shapes and sizes of the mold used, the temperature of molding, the quickness and temperature of the cooling process, and the material used to make the parts, obtaining an airtight seal is extremely difficult and costly.
The present invention provides for a closure which is self-closing after the consumer has finished dispensing the desired amount of product.
Also, the present invention provides for a self-closing cap which does not interfere with packaging aesthetics.
Further, the present invention provides for a self-closing cap which is simple and cost effective to manufacture.